Electronic devices, such as microprocessors, microcontrollers, input/output devices, and memory devices, have become increasingly more powerful. For optimal performance, such devices operate at high clock speeds. Increased speeds lead to increased power usage by devices, which in turn means that a greater amount of heat is generated by such devices during operation. An effective heat dissipation mechanism is thus needed to prevent excessive heat buildup in the devices, which may damage the devices or reduce their reliability. Operational integrity can also be adversely affected when a device is overheated.
One type of heat dissipation mechanism includes an airflow generator to force a flow of air in a system. Heat sinks are thermally contacted to heat-producing devices to increase heat dissipation with extended surface area. As heat dissipation loads of devices (such as high performance microprocessors, system controllers, and so forth) continue to increase, larger heat sinks are needed. Large heat sinks tend to be relatively heavy. This is particularly the case for large heat sinks formed of thermally conductive metals, such as copper or aluminum.
When mounted directly on components, heavy heat sinks can cause reliability problems. For example, certain types of integrated circuit (IC) packages are easily damaged by the pressure and torque applied by a heavy heat sink, both during static operating conditions and during transit conditions (e.g., shipping). Further, a heavy heat sink can damage the connection between a component and a board on which the component is mounted. Also, if several heavy heat sinks are located on a circuit board, the weight of the heat sinks can deform the circuit board, which reduces reliability of the circuit board.
Additionally, heavy heat sinks usually require relatively complex and costly retention and support mechanisms within the system. Various constraints thus serve to limit the size and weight of heat dissipation components and potentially the effectiveness of such heat dissipation components.